Rinse and sort the beluga lentils. Combine the lentils, black quinoa, and 1½ cups water in a small saucepan and bring to a boil. Reduce heat to low, cover, and simmer until the grains are tender and water has been absorbed, about 20 to 25 minutes. If your lentils and quinoa are ready and there is a little water left over, simply drain.
Combine the apple cider vinegar, turbinado sugar, 1 cup water, and a pinch of salt in a second small saucepan and bring to a boil. Peel and thinly slice the red onion into rounds. Add the sliced red onion to the second saucepan (with the vinegar). Turn off the heat, and transfer the pickled onion and liquid to a heatproof bowl to chill in the refrigerator until Step 6.
Peel and mince 1 clove garlic. Halve the lime and cut half into wedges. In a small bowl, combine the juice from half the lime, minced garlic, yogurt, dried oregano, cumin, ¼ tsp salt, and a pinch of pepper. Mix the citrus cumin dressing until well-combined.
Trim the green beans. Cut the yellow squash in half lengthwise and then into half moons. Peel the husks from the corn and cut the kernels off of the cob. Destem the kale and roughly chop the leaves. Add the chopped kale to a large bowl with 1 tsp olive oil and a pinch of salt. Massage until the kale begins to soften, about 1 minute.
Place a large nonstick skillet over high heat with 1 tbsp olive oil. Add the green beans, yellow squash, corn, and a pinch of salt and pepper. Cook until the vegetables are charred in places, about 3 to 5 minutes.
Divide the massaged kale between large bowls. Top with lentils and quinoa, pickled onions, and charred vegetables. Drizzle with citrus cumin dressing. Serve with remaining lime wedges.